Baking device and method

ABSTRACT

The invention relates to a device ( 1 ) for producing bakery products ( 2 ). It has an oven ( 4 ) closed off by a door ( 5 ) and a heating device ( 7 ) which heats the oven ( 4 ). A delivery device ( 10, 31 ) is also provided for a fluid ( 11 ), along with a discharge element ( 12 ) arranged in the oven ( 4 ), a storage container ( 22 ) and a conveyor device ( 20 ) for the fluid ( 11 ). A sensor ( 8, 9 ) is arranged in the oven ( 4 ) for detecting at least one actual value for a temperature in the oven ( 4 ) and which is connected to a control device ( 16 ). The latter is also connected to the heating device ( 7 ), the delivery device ( 10, 31 ) for the fluid ( 11 ) and an energy source ( 21 ). At least one other sensor ( 8, 9 ) is provided in the oven ( 4 ) for detecting an actual value of the humidity and is connected, along with a clock timer ( 30 ), to the control device ( 16 ). The control device ( 16 ) is connected to the input units ( 26, 27 ) for a desired value for the humidity and/or the temperature, which, as is the case, may depend on a baking or cooking time which can be pre-set by means of the clock timer ( 30 ).

[0001] The invention relates to a device for making bakery products anda method of cooking and/or baking foodstuffs or bakery products asdefined in the preambles of claims 1 and 10.

[0002] Various devices for making bakery products, in particular forcooking and/or baking foodstuffs or bakery products, and a correspondingmethod are known. Document AT 401 707 B stipulates the temperatures andhumidity to be applied both during preparation of the dough and duringwhat is referred to as the proving time. In addition, the main provingprocess is interrupted before it is completed. This prevents a skin fromforming prematurely on the baked products so that the steam, generatedsubsequently when baking previously deep-frozen bakery products andoccurring at a relatively late point in the baking or cooking process,does not cause the skin to burst in the region of the top surface of thebakery products. All that is said about conditions pertaining to thebakery goods during baking is that when they have been placed on thebaking tray, the bakery products should be sprayed with water and thenbaked using the most possible steam (steaming), which means that bothhot air ovens as will as fan-assisted ovens can be used. Thedisadvantage of this is that it is not possible to delay or prevent theearly formation of a skin on the bakery products during final finishingof the same baking process with any degree of reliability.

[0003] The objective of this invention is to provide a device of thetype outlined above, as well as a method of cooking and/or bakingfoodstuffs or bakery products by means of which the cooking or bakingprocess can be universally adapted to different conditions.

[0004] This objective is achieved by the characterising features set outin claim 1. The advantage gained is that by constantly monitoring adesired and an actual value of the humidity and/or temperature in theoven in relation to the cooking or baking temperature and/or cooking orbaking time, it is possible to prevent either excessive drying or toohigh a humidity at the surface of the bakery products as well as theformation of a skin in the region of the bakery products which isundesirable or occurs too late. Furthermore, the foodstuffs or bakeryproducts are cooked or baked evenly.

[0005] This also makes it easy to control steam or other ingredientsreleased from the foodstuffs or bakery products, which means that thefinished cooked or bakery products can be improved, namely theappearance of the foodstuffs or bakery products as well as theirconservation and freshness, in particular their crispiness, which can bemaintained for a longer period. Another advantage of this solutionresides in the fact that the respective humidity and the respectivetemperature in the oven in which the foodstuffs or bakery products areplaced remains constant without any additional intervention, e.g. anextra measuring process.

[0006] By means of the embodiment defined in claim 2, the actual valueof the humidity and/or temperature can be taken into account overallduring the subsequent cooking or baking process, which means that it isalso possible to adapt changes in temperature and the timing of thecooking or baking process so that the quality produced represents anoptimum between the desired cooking or baking result and the cooking orbaking time.

[0007] Another embodiment defined in claim 3 offers an advantage sinceit allows a sensitive adjustment of the temperature in the oven.Accordingly, the difference between the desired and actual value orvariance from the desired value relating to the temperature and/orhumidity content can be kept low.

[0008] Another embodiment specified in claim 4 is such that the humidityvalue can be rapidly adapted to different production stages and acooking or baking process optimised.

[0009] There are also advantages to be had from an embodiment defined inclaim 5 because the entire cooking or baking process can be monitored.This means above all that the entire cooking or baking process can becontinuously and constantly monitored so that, depending on the cookingor baking time and depending on the sensitivity of the foodstuff to becooked or the products to be baked, the timing between the individualpoints at which the actual value of the humidity and/or temperatureand/or cooking time and/or difference is detected can be universallyadapted to suit different applications.

[0010] With the embodiment defined in claim 6, it is also possible todetect the setting of the temperature and/or the humidity temperatureand/or the humidity and the difference between them and a relateddesired value depending on the duration of the cooking or bakingprocess.

[0011] The design of the control device defined in claim 7 enablessensitive monitoring but also allows the cooking or baking process to beregulated.

[0012] The options for selecting how the fluid is introduced, as set outin claim 8, have an advantage in that they allow adaptation to thedesired change in humidity in the oven.

[0013] The embodiment outlined in claim 9 provides a simple means ofproducing an even humidity and/or temperature across the entire volumeof the oven.

[0014] The objective of the invention is also achieved by the methodoutlined in claim 10. The advantage of this method is that by constantlymonitoring the actual values of the humidity and temperature in the ovenand by constantly comparing them in order to establish any variance fromthe desired values, the cooking or baking process can be universallyadapted to produce a favourable finished result from the cooking orbaking process.

[0015] The features outlined in claim 11 also offer advantages sincemonitoring the difference between the desired and actual values meansthat the variance of the actual value from the desired value can be keptto a minimum, so that external conditions such as fluctuations in theinput of the power supply to the heating device as well as differentquantities loaded in the oven for example, and of course differences inthe humidity and/or temperature of the foodstuffs or bakery productsbeing cooked or baked, can be taken into account in a simple, fullyautomated manner, without the need for extra work processes.

[0016] The invention will be described in more detail in relation to anembodiment illustrated in the drawing.

[0017] This drawing:

[0018]FIG. 1 is a very simplified, schematic illustration of a device asproposed by the invention for producing bakery products, seen from afront view, showing the associated control device in a block diagram.

[0019]FIG. 1 illustrates a device 1 for producing schematicallyillustrated bakery products 2, e.g. bread rolls, croissants and similar.An oven 4 arranged in a housing 3 is accessible from a front face bymeans of a door 5, the door 5 being fitted with a transparent glass pane6, making it possible to keep an eye on the cooking or baking process.

[0020] The oven 4 co-operates with a heating device 7 which heats theoven 4. The heating device 7 may be of any design having any featureknown from the prior art and may be operated by any medium such as gas,electricity, oil or solid fuels. Clearly, other heat-generating devicesmay also be used such as micro-waves, high-frequency systems, etc., andthe energy supply may also be provided by feeding in hot air.

[0021] Arranged in the interior of the oven 4 is at least one sensor 8for detecting an actual value for the temperature and at least one othersensor 9 for detecting the actual value of the humidity in the oven 4.Also provided in the oven 4 is a delivery device 10 for a fluid 11 inorder to regulate the humidity and/or temperature in the oven 4. Thisdelivery device 10 has at least one discharge element 12 in the oven 4for the fluid 11.

[0022] Clearly, several discharge elements 12 may also be provided andthese may be arranged distributed around an interior chamber or aninterior surface of the oven 4 in any layout.

[0023] Amongst other things, the fluid 11, particularly if supplied inliquid form, may also be fed into a catchment container in the interiorof the oven 4, from where it can be emitted in a gaseous or vapour stateas a result of the heat prevailing in the oven 4.

[0024] There may be an advantage to be had if the discharge elements 12,which may be spray nozzles, atomiser nozzles and similar, are evenlydistributed across a cover plate 13 of the oven 4 because, as the fluid11 flows in, regardless of whether in liquid, gaseous or vapour state,this steam will be heavier due to the difference in temperature of thesteam relative to the air temperature in the oven 4 and will thereforemove down in the direction of a floor 14 of the oven 4, thus beingevenly distributed across virtually the entire volume of the oven 4.

[0025] However, if several baking trays 15 holding bakery products 2 areplaced in an oven 4, it may be of advantage to provide evenlydistributed discharge elements 12 for the fluid 11 around the peripheryof the oven 4, at least around the side walls and rear wall thereof,respectively in the region between two baking trays 15, so that moisturecan be duly applied to the bakery products in each position, allowingthe moisture input and stabilisation to be finely controlled.

[0026] This being the case, it may also be advantageous to arrangesensors 8 and 9 for the actual temperature and humidity values in theintermediate space so that a control device 16 can be specificallydesigned—as will be explained in more detail below—to determine thedesired values for temperature and/or humidity individually for eachbaking tray 15.

[0027] This control device 16 is connected to a conveyor device 20 forthe fluid 11, the delivery device 10, the heating device 7 and an energysource 21 by means of lines 17, 18, 19.

[0028] The conveyor device 20 may draw off the fluid 11 from a storagecontainer 22 or from a system of pipework or the fluid may be drawndirectly through a valve of the piping system operated by the controldevice 16.

[0029] It is also possible to provide, between the conveyor device 20and the discharge element 12 or at any other random point, a steamgenerator 23 so that the fluid 11 can be converted from a liquid to avapour state.

[0030] Clearly, however, in addition to the discharge elements 12 forthe fluid 11 in liquid state, it would also be possible to provideelements for discharging the fluid 11 in a vapour state, in which casethe conveyor device 20 and - as shown by an additional line 17 - thesteam generator 23 would also be operated by the control device 16 inorder to apply the fluid 11 in different states, for example by applyingsteam or water vapour or micro-fine droplets and/or at different pointsof the oven 4.

[0031] Sensors 8 for detecting temperatures in the oven 4 and sensors 9for detecting humidity in the oven 4 are connected to the control device16 by means of lines 24.

[0032] As indicated by broken lines, several such sensors 8, 9 and/orsensors 9 can be provided and the person skilled in the art may selectthe layout and distribution of these sensors 8, 9 on the basis of hisspecialist knowledge of the field, these not being tied or restricted tothe particular embodiment illustrated here. As denoted schematically bybroken lines, sensors 8, 9 of this type may also be arranged in anintermediate space 25 between two baking trays 15, e.g. around theperiphery or a part-circumference of the oven 4.

[0033] Furthermore, the control device 16 may be provided with inputunits 26, 27 for entering a desired value for humidity or temperature inthe oven 4. Clearly, the input units 26, 27 are illustrated here on afunctional basis only and any other technical means, e.g. keyboards, maybe used with the requisite software units or computers and personalcomputers for and in conjunction with the control device 16.

[0034] The desired values entered for humidity and temperature maydepend on the length of the cooking or baking time, such as a definedtemperature for specific humidity values or vice versa, and thetemperature can be set on the basis of the cooking or baking timeelapsed in conjunction with the humidity, or the elapsed baking andcooking time can be predetermined by correlating the temperature withthe desired humidity value.

[0035] Any cooking and baking process can be carried out with the device1 and in the oven 4 and it is therefore possible to process doughportions for bakery products 2, e.g. immediately after the mainfermentation or what is referred to as the proving time, in the oven 4or, accordingly, deep-frozen or pre-frozen bakery products, which havebeen previously frozen as dough portions or already part-baked andfrozen.

[0036] When using pre-frozen or frozen dough portions, for example, itcan be of advantage to insert a schematically illustrated probe 28 inthe bakery products 2, which can also be connected to the control device16 by means of a line 29 in order to detect the temperature and/ormoisture content of the bakery products 2 on a continuous basis, andthese detected actual values can then be used for computing the desiredvalues for temperature and humidity in the oven 4.

[0037] The method of cooking or baking foodstuffs or bakery products 2may proceed as follows:

[0038] The bakery products 2 are laid out on a baking tray 15, havingbeen pre-processed or not depending on the production process, e.g.directly after the proving time or in a frozen or cooled state. Afteropening the door 5, this baking tray 15 is placed in the oven 4, inparticular pushed along matching guide tracks. Depending on the cookingor baking process to be carried out, the oven 4 may have been pre-heatedto a desired temperature, for example, and the air in the interior ofthe oven 4 set to a requisite desired value for air humidity. The oven 4may be preheated and the corresponding air humidity in the interior ofthe oven 4 pre-selected via the control device 16, these values beingstored in an operating programme, which may be of any one of the mostvaried of types known from the prior art, in the control device 16.

[0039] Depending on the set or selected cooking or baking programme, theactual value of the temperature and/or the humidity in the oven 4 isconstantly monitored by the sensors 8, 9 and these data are eithercontinuously applied to the control device 16, e.g. in real time orintermittently at specific time intervals, or respectively after acertain time of the cooking duration has elapsed, or alternatively whencertain pre-selected temperature levels have been reached. Clearly, thetiming used to detect the actual value for the air humidity and theactual value for the temperature can be phased relative to one another.

[0040] In order to monitor the baking time, the control device 16 has aclock timer 30. This may also be used to determine sampling of theactual values, which will be defined beforehand depending on thetemperature and the cooking or baking time on the basis of the desiredvalues set for temperature and humidity via the input units 26, 27.These definitions and desired values may clearly also be integrated in acorresponding computer programme or may be predefined in memory units -depending on the programme run - and continuously compared with theactual values for temperature and humidity.

[0041] If the control device 16 ascertains that the actual value forhumidity is at variance with the desired value, the actual value forhumidity will be reduced to the desired value by feeding in dry air ordrawing off moisture, for example, and, if the humidity in the oven 4 istoo low, fluid 11 in liquid, gaseous or vapour form will be fed in toincrease the moisture content until the actual value matches the desiredvalue again.

[0042] In order simultaneously to keep the temperature constant, reduceor lower the temperature in the oven 4, the fluid 11 fed in may be inthe most varied of states, e.g. as a liquid at the most varied oftemperatures, e.g. cooled as steam or as hot steam or over-heated steam,in order to maintain, lower or raise the temperature simultaneously withthe increase in humidity.

[0043] Simultaneously or regardless thereof, the temperature can bemonitored accordingly and if there are any variances in the actual valuefrom the desired value, either cool, cooled or deepfrozen air can be fedin via the delivery device 10, 31 or via a separate delivery device 31,in order to reduce the temperature and, for example, to allow hot steamor wet steam to circulate so as to raise the temperature abruptly - as asupplement to the heating device 7 provided anyway. The temperature maybe regulated by means of the delivery devices 10, 31 or also byexchanging the air in the interior of the oven 4 or by an exchange ofheat. In addition, by using a regulating mechanism to adapt to thedesired value, it is possible to set this as standard for the entireoven 4 or to provide appropriate units and means alternately forindividual baking trays 15 or individual regions of the oven 4 in orderto adapt the temperature to the actual values in certain regions.

[0044] For example, in order to adapt or maintain the desired value ofthe temperature and/or humidity, it is possible to use what are referredto as misters which distribute vapour, hot or wet steam in the oven 4.

[0045] One of the advantages of the proposed method resides in the factthat by using this control device in the manner described, the oven 4can be used universally for different cooking and baking purposes andother processes such as baking, roasting, steaming, thawing and similar.Due to the option of fully automated operation or “self-learningoperation”, there is no longer any need to take account of thetemperature and/or humidity or the temperature of the moisture and thequantity when the oven 4 is loaded. For example, the actual values forthe temperature and/or moisture content of the foodstuffs or bakeryproducts 2 can also be detected with one or more probes 28 and there isthen no need to take account of different cooking quantities,temperatures and moisture levels in the foodstuffs or bakery products 2in the oven 4 to regulate the control device 16.

[0046] As a result of this automatic regulation system, the controldevice 16 produces an optimum cooking and/or baking process by selectingthe humidity and/or temperature - on the basis of the set actualvalues - in which case, in the preferred approach, the differencebetween the desired and actual value for temperature and/or humidity ofthe cooking or baking process is constantly and continuously detectedwhen different quantities or volumes of foodstuffs and/or bakeryproducts 2 are inserted and preferably above all if these are ofdifferent moisture contents and/or temperatures. Accordingly, an optimumbaking and cooking process can be produced irrespective of whetheroperating personnel are to hand, even under different operatingconditions, and can be so without the disadvantage of setting errorswhich might occur with manual input and without the need to loadindividually staggered programmes specifically set up to processdifferent conceivable quantities and/or temperatures of bakery productsand/or moisture content of the bakery products. This reduces settingrequirements for the programmes and, accordingly, maintenance timewhilst ruling out operator errors.

[0047] Consequently, the cooking or baking programmes can be set up tomaximise capacity of the oven 4 and the programme run can be optimisedon a fully automated basis—in terms of temperature and humidity—whenprocessing smaller quantities in the oven 4 so that the cooking orbaking result will be constant regardless of the quantity in the oven.

[0048] Clearly, the device and method described can also be used for allother processes such as roasting, steaming, stewing and/or thawingfoodstuffs or bakery products 2.

[0049] The device and method described can be supplemented by providingthe device 1 with a microwave generator 32, thereby enabling the ovenand the foodstuffs or bakery products contained in it to be heated bymicro-waving. Particularly when processing frozen foodstuffs or bakeryproducts 2, this will make it possible at the start of processing, i.e.heating, simultaneously and/or in advance and/or after the heat has beenallowed to act on the foodstuffs or bakery products 2 for a specifictime, to heat the interior of the foodstuffs or bakery products 2 bymeans of the microwave action.

[0050] By heating the central region, the water vapour which occurs canbe released more easily through the surface without removing the surfacelayers, allowing the central regions of the foodstuffs and bakeryproducts 2 to expand unhampered so that the final cooked process orfinal baking process will be uniform throughout the entire volume of thefoodstuffs or bakery products 2.

[0051] Within the context of the invention, it would clearly also bepossible to apply the method proposed by the invention in conjunctionwith other methods known from the prior art.

List of Reference Numerals

[0052]1 Device

[0053]2 Bakery product

[0054]3 Housing

[0055]4 Oven

[0056]5 Door

[0057]6 Glass pane

[0058]7 Heating device

[0059]8 Sensor

[0060]9 Sensor

[0061]10 Delivery device

[0062]11 Fluid

[0063]12 Discharge element

[0064]13 Cover plate

[0065]14 Floor

[0066]15 Baking tray

[0067]16 Control device

[0068]17 Line

[0069]18 Line

[0070]19 Line

[0071]20 Conveyor device

[0072]21 Energy source

[0073]22 Storage container

[0074]23 Steam generator

[0075]24 Line

[0076]25 Intermediate space

[0077]26 Input unit

[0078]27 Input unit

[0079]28 Probe

[0080]29 Line

[0081]30 Clock timer

[0082]31 Delivery device

[0083]32 Microwave generator

1. Device (1) for cooking and/or baking foodstuffs or bakery products(2), having an oven (4) with a heating device (7) for the oven (4), adelivery device (10) for a fluid (11), a discharge element (12) arrangedin the oven (4) and at least one sensor (8) for detecting at least oneactual value of a temperature in the oven (4) and having a controldevice (16) connected to the heating device (7), the sensor (8) as wellas to the delivery device (10) and an energy source (21), whereby atleast one other sensor (8, 9) connected to the control device (16) isprovided in the oven (4) for detecting an actual value of the humidity,characterised in that the control device (16) is connected to an inputunit (26, 27) for a desired value pertaining to the humidity and/ortemperature which, as is the case, will depend on a baking or cookingtime which can be set by means of a clock timer (30), and in that thedelivery device (10, 31) is designed for the delivery and discharge ofmoisture.
 2. Device according to claim 1 , characterised in that when adifference occurs between the desired and actual values of the humidityand/or the desired and actual values of the temperature and/or therespective cooking or baking time, the humidity and/or the temperaturein the oven (4) can be restored by delivering or discharging moistureand/or heat by means of the delivery device (10, 31) and/or restored tothe desired value.
 3. Device according to claim 1 or 2 , characterisedin that if the desired temperature in the oven (4) is exceeded, thedelivery device (10, 31) is activated by means of the control device(16) so as to deliver fluid (11) and/or cool air to the oven (4). 4.Device according to one or more of the preceding claims, characterisedin that if the desired humidity in the oven (4) is exceeded, thedelivery device (10, 31) is activated so as to draw off moisture or feedin dry fresh air.
 5. Device according to one or more of the precedingclaims, characterised in that the control device (16) preferably detectsthe difference between the desired and actual values of the humidityand/or temperature in the oven (4) on an intermittent basis.
 6. Deviceaccording to one or more of the preceding claims, characterised in thatthe difference between the desired and actual values of the temperatureand/or the humidity can be set in accordance with at least onepre-settable timing value for the cooking and/or baking duration and/oron the basis of pre-settable values for the temperature in the oven (4).7. Device according to one or more of the preceding claims,characterised in that the control device (16) preferably has aprogrammable computer, which has at least one memory unit for storing atleast one desired value for the humidity and/or the temperature and/orthe cooking or baking time.
 8. Device according to one or more of thepreceding claims, characterised in that the fluid (11) can be introducedand/or blown into the oven (4), preferably at above atmosphericpressure, in a liquid and/or gaseous and/or vapour state, in particularas water vapour.
 9. Device according to one or more of the precedingclaims, characterised in that the discharge elements (12) for the fluid(11) are arranged distributed across the surface facing the oven (4), inparticular across cover plate (13).
 10. Method of cooking and/or bakingfoodstuffs or bakery products (2) in an oven (4), with a device (1) inparticular according to one or more of the preceding claims, whereby thefoodstuffs and/or bakery products (2), preferably deep-frozenbeforehand, are heated for cooking and baking or pre-cooking or andpre-baking purposes and a humidity level can be pre-set for thispurpose, characterised in that desired values are pre-defined for thetemperature and humidity, depending, as is the case, on the cooking orbaking time, after which, whilst the foodstuffs or bakery products (2)are cooking and baking, the respective actual values for the humidityand/or the temperature are detected accordingly depending on the cookingor baking time, whereby on establishing an actual value for thetemperature and/or the humidity which smaller than the correspondingdesired value, the adjustment to the desired values is performed bywater vapour which is produced in the device itself.
 11. Methodaccording to claim 10 , characterised in that, by feeding in or drawingoff moisture, the humidity and, by applying or drawing off heat, thetemperature of the bakery products can be restored to the desired value.